The role of seismic surveying in coal mining exploration

Abstract

The use of both high resolution surface seismic reflection surveys and in-seam seismic techniques in the exploration of coal is described in this paper. In the past, the traditional method for exploration for coal was by means of vertical boreholes both on land and offshore. This has now been augmented by the development and application of new high resolution surface seismic techniques to give valuable information on the geological structure for both new mine prospects and extension areas to existing mines. The recently developed in-seam seismic method is applied underground on the coal face itself. The area ahead of that currently being mined is investigated and it is possible to detect small but important faults that are not detectable from the surface. The combined approach gives both small- and large-scale structure. These techniques have been developed successfully only because it was recognised that standard oil industry seismic methods were far from optimal for coal exploration. Data acquisition and processing must be designed for the problem to hand. The extra cost of this is more than justified by the quality of information that is obtained. Surface seismic methods provide information that is mainly of strategic value, whilst that of the in-seam method is essentially tactical. The combined data base, drilling, and both surface and underground seismic surveying is vital in producing a three dimensional model for deep mining operations where the uncertainty of geological conditions and structure can play a deciding role in the viability of a new project. Examples of recent applications of these techniques are given to demonstrate their value.